bad idle when cold

[dan619]

I have a 1993 nissan altima GXE. The car is runs great and has done me good. Recently when i start the altima in the morning and the engine is cold it runs rough. It almost sounds like the engine has bad motor mounts. Very loud vibration from the engine. When the engine reaches the right operating temp. its runs fine and the vibration goes away. I' changed the cap, plugs, wires, air and fuel filter. Any ideas? I also had the timing checked.! Please help thanks
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[InnerDragon103]

well, keep in mind that you own a 12 year old car.. the same happens with my 94 altima.. just old age -- see if the idle is low, MAYBE raise it with the idle adjust screw just a bit if you want, but dont put it too high or the car will idle too highly when warm, you know?

[JustSayGo]

Just ideas. Vacuum leaks could cause a cold missfire problem. Check vacuum hoses and the gasket between the intake manifold and the cylinder head. Check that there is no vacuum to the EGR valve. I am sure that if an engine runs well when it is warm, it can run great while it is warming up no matter how old it is.

[dan619]

Originally Posted by JustSayGo

Just ideas. Vacuum leaks could cause a cold missfire problem. Check vacuum hoses and the gasket between the intake manifold and the cylinder head. Check that there is no vacuum to the EGR valve. I am sure that if an engine runs well when it is warm, it can run great while it is warming up no matter how old it is.

Yes i agree. I am also going to check the Coolant Temp Sensor. I really think this is the prob. Thanks for you're info. Ill let you know how things work out.

[JustSayGo]

The Haynes Repair Manual says, a bad CTS should set a code 13. Is your service eng soon light on? What the CTS does is send the "engine reaching operating temperature" message to the ECM. That is the point that the computer control system begins closed loop operation useing the input messages from the other sensors to adjust ignition timing and fuel delivery. Your decription sounds like the vibration goes away when the system goes into closed loop. If any sensor or sensor circuit is malfunctioning the eng light should stay on indicating a code stored by the ECM .